1. Field of the Disclosure
The invention relates to an optical device and a manufacturing method thereof; more particularly, the invention relates to a projection screen and a manufacturing method thereof.
2. Description of Related Art
Micro-structures including inclined refraction/reflection surfaces for changing directions of beams, a micro-lens array for converging beams, a diffusive structure for scattering projection beams, and a light absorption structure for absorbing ambient beams may be configured on a projection screen.
However, the difficulty in aligning front and rear surfaces of the projection screen significantly complicates the manufacturing process of projection screen. In addition, conventional light absorption layers excessively absorb the projection beams, such that energy utilization efficiency is unavoidably reduced. Said issue of the utilization efficiency of the projection beams still need to be improved.
According to the disclosure of Europe patent publication no. 0311189A1, a Fresnel lens structure constituted by light incident surfaces and edges is formed on the front surface of a projection screen, wherein each of the light incident surface has micro-lenses for scattering the incident beam into beams, and each of the edges serves to absorb beams. China patent publication no. 102023471A discloses a reflective micro-lens array in which parts of beams emitting from a projector are absorbed by a light absorption layer. Taiwan Patent no. 1378314 discloses a plurality of light mixing chambers and a plurality of lens structures. U.S. patent publication no. 20050057804A1 discloses a projection screen.